Conventionally, WebSocket is known as a Web standard communication protocol for eliminating reconnection costs by maintaining established communication connections so as to achieve low delay. WebSocket is used, for example, in applications such as so-called smart remote control for transmitting control commands from a mobile terminal such as a smart phone via a relay server to customer premises equipment or the like connected to a network to control the equipment.
In order to respond to concurrent connections by a large number of clients, companies who provide such applications as services may provide a plurality of relay servers to cause the WebSocket connections with terminal devices, such as mobile terminals and customer premises equipment, to be dispersed among the plurality of relay servers. In this case, communication performance by the terminal device may vary depending on a loaded condition, a terminal connection number, and the like of the connected relay server. Accordingly, there is need for construction of a mechanism to properly determine with which relay server a terminal device that newly requests connection is to be connected.